The invention concerns more specifically a movement for a timepiece comprising at least one display ring which is rotatably mounted about an axis on bottom a plate and which carries, on the top surface thereof, markings provided in order to appear in a display zone, wherein the ring is fitted with an inner peripheral toothing which cooperates with drive means such that the markings carried by the ring pass into the display zone, and which cooperates with a jumper spring effect stop device, mounted on the bottom plate, able to stop the ring in a determined angular position by abutting radially against the inner toothing, the stop device being drawn towards its radial abutting position by an elastic return element, and wherein a holding plate is secured to the bottom plate so as to retain the stop device axially.
The assembly operations for this type of movement can cause problems, in particular when the holding plate is being secured to the bottom plate. Indeed, the jumper spring and its elastic return element are to be held in position on the bottom plate, in the loaded or wound state, via the holding plate that covers them. Consequently, once the jumper spring and its elastic return element have been mounted, the elastic return element can easily be ejected following a bump or vibration, before the holding plate is completely in place, which complicates assembly operations.
In order to overcome this problem, U.S. Pat. No. 3,893,289 proposes mounting the jumper spring and the elastic return element on the bottom plate prior to the display ring, consequently in the net state and arranging notches in one end of the holding plate so as to allow the display ring to be mounted on the bottom plate after the holding plate has been secured.
It is an object of the present invention to propose an alternative solution to the aforementioned technical problem, while simplifying the assembly operations compared to the solution proposed in U.S. Pat. No. 3,893,289.